This ones going to be short and sweet, fortunately.
I've done a LOT of repetitive testing with a 7900x here to replicate why some users have slow boot issues of what they mistakenly call 'memory training', and i did not want this lost hundreds of pages into the Zen Garden clubhouse thread where no one would see it.
It's usually down to one of two things
1: A physical issue like a too-tight or imbalanced CPU cooler causing poor contact. Don't tighten one side of a cooler all the way and shift over, do them evenly. Clean the pads on the CPU from fingerprints.
2: Incorrect BIOS settings, probably copied from what "everyone says is best"
DDR speeds are 'doubled' so 6000 MT/s RAM (incorrectly sold as 6000 MHZ) is actually 3000 MHZ. This is what confuses beginners.
MCLK is the true memory clock, double it for DDR speeds.
FCLK is the Infinity fabric, that seems to need to be within a certain multiplier range of the MCLK - any value dividable by 0.25x (1.5x, 2.75x 3x, etc) This is critical.
People suggest 3000/2000/3000 is the dream settings for DDR5 6000, and it is. However, there's very little information on what to do if your PC has issues with that.
1. Higher is not always better - Look at the insane latency on the first result.
2. Lower is not always slower. 1800Mhz was only 0.009% slower than 2000, while being faster than 2067.
3. You can only run UCLK at half or full speed, halving has around a 3ns penalty. If you fix stability issues by halving it? Do so!
Put simply, not every CPU and motherboard are going to handle the Fclk at 2000 - lower it to 1800 and see if your slow boot issues go away.
Use AIDA64's cache and latency test and check your own system - sometimes the math is not perfect due to internal mysteries and rounding errors.
As an example DDR5 7200 runs extremely easily on this Asrock Taichi Carrara with Uclk halved, and the latency is lower than the DDR5 6000 testing when it's commonly believed that's not possible.
3600 MCLK divided by 2066 IF maths out to 1.74x and gives great results for XMP on with no manual tweaking.
I Also have some DDR5 8000 i'll be testing in the coming days, knowing how these values need to be in sync is more complex than the old 1:1 days but also more freedom as long as you do some basic math first!
